Optimisation of electrophoretic deposition parameters in coating of metallic substrate by hydroxyapatite using response surface methodology

Hydroxyapatite bioactive coating was deposited on treated medical grade stainless steel 316L by electrophoretic deposition. Two independent variables including deposition voltage and time span were evaluated in order to investigate their effect on substrates’ corrosion potential and coating mass. After deposition, coated substrates were post-treated in a vacuum furnace at 800 °C. The experimental plan was based on a central composite design to create a precision of the mathematical models. The precision of mathematical model and relative parameters were evaluated by variance analysis. Optimum parameters value, considered as simultaneous minimum ion release and maximum coating mass, were predicted at the deposition voltage of 25.93 V and deposition time span of 159 s. The validity of the model generated by response surface methodology was evaluated by comparing the predicted and experimental results. In addition, close agreement between experimental and predicted results was observed